The present invention relates to a multiturn rotary encoder (hereinafter also briefly designated as “MT rotary encoder”) for detecting both a fine-resolved position and a fine position (absolute angle within one 360° revolution), and a number of full, or complete, 360° revolutions (revolution counting). Additionally, the invention relates to a method for determining an unambiguous position of an encoder shaft, which rotates about a rotational axis, with an energy-self-sufficient multiturn rotary encoder configured to detect the number of completely passed 360° revolutions of the rotating encoder shaft as well as to detect an absolute rotational angle, which indicates a fine-resolved position within one 360° revolution of the encoder shaft, wherein an excitation magnet is mounted in a rotationally fixed manner to the encoder shaft for generating an external magnetic field which is used at least for determining the fine-resolved position.